src/main/java/com/google/devtools/build/lib/actions/ActionLookupValue.java

// Copyright 2014 The Bazel Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//    http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package com.google.devtools.build.lib.actions;

import com.google.common.collect.ImmutableList;
import com.google.devtools.build.skyframe.SkyValue;
import javax.annotation.Nullable;

/** Base interface for all values which can provide the generating action of an artifact. */
public interface ActionLookupValue extends SkyValue {

  /**
   * Returns a list of actions registered by this {@link SkyValue}.
   *
   * <p>Null if this value was deserialized with analysis caching.
   */
  @Nullable
  ImmutableList<ActionAnalysisMetadata> getActions();

  /** Returns the {@link Action} with index {@code index} in this value. Never null. */
  default Action getAction(int index) {
    ActionAnalysisMetadata result = getActions().get(index);
    // Avoid Preconditions.checkState which would box the int arg.
    if (!(result instanceof Action action)) {
      throw new IllegalStateException(String.format("Not action: %s %s %s", result, index, this));
    }
    return action;
  }

  default ActionTemplate<?> getActionTemplate(int index) {
    ActionAnalysisMetadata result = getActions().get(index);
    // Avoid Preconditions.checkState which would box the int arg.
    if (!(result instanceof ActionTemplate<?> actionTemplate)) {
      throw new IllegalStateException(
          String.format("Not action template: %s %s %s", result, index, this));
    }
    return actionTemplate;
  }

  /**
   * Returns the number of {@link Action} objects present in this value.
   *
   * <p>There are no actions for deserialized values.
   */
  default int getNumActions() {
    if (getActions() == null) {
      return 0;
    }
    return getActions().size();
  }
}